Recent studies have found that as many as one in five Americans have experimented with some form of sexual non-monogamy, and approximately one in fifteen knows someone who was or is polyamorous. The mainstream media has increasingly covered polyamorous lifestyles and the committed relationships of throuples, and dating apps have added polyamory as a status option.

This book is the first history to trace the evolution of polyamorous thought and practice within the broader context of American culture. Drawing on personal journals and letters, underground newsletters, and publications from the Kinsey Institute Archives, among other sources, it reconstructs polyamory's intellectual foundations, highlighting its unique blend of conservative political thought and countercultural spiritualism. Christopher M. Gleason locates its early foundations in the Roaring Twenties among bohemians. In the 1950s and 1960s it surprisingly emerged among libertarian science fiction writers. Throughout the 1990s, polyamorists utilized the internet to spread their ideas, often undermining any remaining religious or spiritual significance their ideas held.

Offering an original perspective on sexuality, marriage, and the family, American Poly reveals the history of polyamory in the United States from fringe practice to a new stage of the sexual revolution.